Since a Mobile Station (MS) has mobility in a mobile communication system, the network can always grasp a position of the terminal and efficiently transmit seamless data received from an external network to the terminal. To this end, the MS can conduct a handover when moving from one base station to another base station. If the terminal moves farther away to a network of another service provider, the terminal can roam onto the network. As described above, management of a location of the MS can be referred to as the mobility management.
A mobility management technique of the conventional mobile communication system can adopt a centralized scheme based on a hierarchical network structure. For example, in a Universal Mobile Telecommunication System (UTMS) network and a System Architecture Evolution (SAE) network which are 3rd Generation Partnership Project (3GPP) standards, a mobility agent for managing mobility can be located on a core network for the centralized mobility management.
The mobility agent can manage binding information of the MS and process data traffic of the terminal. A Packet Data Network (PDN) Gateway (P-GW) can correspond to a centralized mobility agent in the 3GPP SAE, and a Gateway General Packet Radio Standard (GPRS) Support Node (GGSN) can correspond to a centralized mobility agent in the UMTS network.
However, such a centralized mobility management technique can have problems.
A first problem can include inefficiency of a routing route. Both traffic transmitted to the terminal and traffic transmitted from the MS can pass through the centralized agent. If all traffic should pass through the centralized agent even though the MS and a Corresponding Node (CN) are located geographically close to each other, data transmission/reception can be delayed.
A second problem can include an error of the centralized agent (such as a single point of failure). As described above, in the centralized mobility management, all traffic can pass through the centralized agent. Accordingly, when the centralized agent malfunctions, communication of the overall network can be paralyzed.
A third problem can include traffic centralization of the core network. Since traffic of all MSs can concentrate on the core network, a scalability problem of the network and equipment can be generated due to traffic overloads. As a result, this can cause as burden that a communication service provider should increase networks and equipment of the core network. Particularly, as communication technologies are developed, a burden of the core network can become more serious because of the development of radio access technologies.